Genetic structure of green ash (Fraxinus pennsylvanica): implications for the establishment ofex situconservation protocols in light of the invasion of the emerald ash borer

2014 ◽  
Vol 12 (3) ◽  
pp. 286-297 ◽  
Author(s):  
Constance E. Hausman ◽  
Michelle M. Bertke ◽  
John F. Jaeger ◽  
Oscar J. Rocha

The USA is experiencing a prolific invasion of the wood-boring emerald ash borer,Agrilus planipennis. Native to Asia, this beetle completes its life cycle on ash trees and results in nearly complete mortality of all infested trees. In the present study, we examined the levels of genetic diversity and differentiation among eight populations ofFraxinus pennsylvanica(green ash) using five polymorphic microsatellite loci. Genetic information was used to design guidelines for the establishment of a seed collection sampling strategy to conserve the genetic diversity of ash trees. We found high levels of genetic diversity, as indicated by the allelic richness, both across the populations (16.4 ± 5.18 alleles per locus) and within them (8.03 ± 1.21 alleles per locus). The expected and observed heterozygosity was also high (0.805 ± 0.38 and 0.908 ± 0.04, respectively), and there was moderate genetic differentiation among the populations (FST= 0.083) with members of these eight populations grouped into three distinct clusters. We examined the relationship between the number of individuals sampled and the number of alleles captured in a random sample taken from a population of 10,000 individuals. Only sample sizes of 100 individuals captured most of the alleles (average = 78.74 alleles), but only seven of 50 samples effectively captured all the 82 alleles. Smaller samples did not capture all alleles. A probabilistic model was used to determine an optimal sampling strategy, and it was concluded that a collection of 200 seeds from each of five mother trees would have the highest likelihood of capturing all alleles in a population.

2011 ◽  
Vol 28 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Toby R. Petrice ◽  
Robert A. Haack

Abstract Efforts to eradicate or slow the spread of emerald ash borer (EAB) (Agrilus planipennis Fairmaire [Coleoptera: Buprestidae]) include cutting infested and nearby uninfested ash (Fraxinus spp.) trees. However, ash trees readily sprout after they have been cut, providing potential host material for EAB. In 2004–2005, we conducted studies to determine how different cutting times (midspring, late spring, and late summer), different cutting heights (0–5, 10–15, and 20–25 cm above the ground), and triclopyr (44% active ingredient) stump treatment of green ash (Fraxinus pennsylvanica Marsh.) trees affected subsequent stump sprouting and colonization by EAB. We also cut white ash (Fraxinus americana L.) and black ash (Fraxinus nigra Marsh.) trees 20–25 cm above the ground in late spring. Some stumps of each ash species tested sprouted and were colonized by EAB. All green ash stumps treated with triclopyr died and were not colonized by EAB. Stump sprouting was significantly lower for stumps cut in late spring compared with stumps cut in midspring or late summer. Stump sprouting did not vary significantly among cutting heights. None of the green ash stumps cut in midspring or cut 0–5 cm above the ground were colonized by EAB; however, the frequency of stump colonization by EAB did not vary significantly among cutting times or cutting heights.


2014 ◽  
Vol 44 (7) ◽  
pp. 768-776 ◽  
Author(s):  
Stephen J. Burr ◽  
Deborah G. McCullough

Assessing emerald ash borer (Agrilus planipennis Fairmaire) impacts in North American forests is essential for projecting future species composition of stands invaded by this phloem-feeding pest. We surveyed all species of overstory trees and regeneration in 2010 and 2011 in 24 forested sites with a major component of green ash (Fraxinus pennsylvanica), representing the Core, Crest, and Cusp of the A. planipennis invasion wave across southern Michigan. By 2011, an average of 78.6% ± 0.10%, 44.8% ± 0.11%, and 19.8% ± 0.07% of overstory ash trees representing 87%, 57%, and 14% of the total ash basal area had been killed in Core, Crest, and Cusp sites, respectively. Green ash seedlings, saplings, and recruits were abundant in all sites, but newly germinated ash seedlings were absent in Core sites and scarce in Crest sites. Canopy gaps resulting from current ash decline and mortality increased available photosynthetically active radiation (PAR) and sapling growth in Crest sites, but PAR was low in Core and Cusp sites. Lateral ingrowth of non-ash overstory trees has largely filled canopy gaps in Core sites, and there was little evidence of green ash recruitment into the overstory. Green ash appears unlikely to persist as a dominant species in forests invaded by A. planipennis.


2016 ◽  
Vol 42 (6) ◽  
Author(s):  
Sara Tanis ◽  
Deborah McCullough

Emerald ash borer (EAB) (Agrilus planipennis), first identified near Detroit, Michigan, U.S., in 2002, has killed millions of ash trees (Fraxinus spp.) in 28 states and two Canadian provinces to date. Trunk injections of insecticide products containing emamectin benzoate (EB) (e.g., TREE-ageR) are often used to protect ash trees in landscapes from EAB, but wounds and potential injury resulting from injections are a concern. Researchers examined 507 injection sites on 61 trees and recorded evidence of secondary wounding (e.g., external bark cracks, internal xylem necrosis and pathogen infection). Researchers assessed 233 injection sites on 22 green ash and 24 white ash trees macro-injected with a low or a medium-high rate of EB in 2008 only, or in both 2008 and 2009. Only 12 of 233 injection sites (5%) were associated with external bark cracks and there was no evidence of pathogen infection. On 39 of the 46 trees (85%), new xylem was growing over injection sites. Researchers assessed 274 injection sites on 15 green ash trees injected annually with EB from 2008 to 2013 or injected in 2008 and again in 2011. Bark cracks were associated with four injection sites on three trees, but no evidence of injury was found on the other 12 trees. All 15 trees had new xylem laid over injection sites. Confocal laser scanning and polarizing digital microscopy were used to assess the integrity of discolored xylem tissue removed from the immediate area surrounding 140 injection sites on 61 trees. Researchers found no evidence of decay associated with discoloration.


Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 338 ◽  
Author(s):  
Drogvalenko ◽  
Orlova-Bienkowskaja ◽  
Bieńkowski

Agrilus planipennis (Coleoptera: Buprestidae) is a devastating invasive pest of ash trees. This wood-boring insect is native to Asia and established in European Russia about 20 years ago. It severely damages Fraxinus pennsylvanica plantations and quickly spreads. In 2019 we first detected A. planipennis in Ukraine. More than 20 larvae were collected from under the bark of F. pennsylvanica trees on 5 September 2019 in the Markivka District of the Luhansk Region. The coordinates of the localities of collection were 49.614991 N, 39.559743 E; 49.614160 N, 39.572402 E; and 49.597043 N, 39.561811 E. The photos of the damaged trees with larval galleries, exit holes and larvae are presented. It indicates that A. planipennis is established in the east of Ukraine. This fact is important for development of quarantine protocols to prevent or at least slow the further spread of this invasive pest in Europe.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 691
Author(s):  
Mark G. Volkovitsh ◽  
Andrzej O. Bieńkowski ◽  
Marina J. Orlova-Bienkowskaja

Emerald ash borer (EAB), Agrilus planipennis, native to East Asia, is an invasive pest of ash in North America and European Russia. This quarantine species is a threat to ash trees all over Europe. Survey in ten provinces of European Russia in 2019–2020 showed that EAB had spread faster and farther than was previously thought. The new infested sites were first detected in St. Petersburg (110–120 km from the EU border: Estonia, Finland) and Astrakhan Province (50 km from the Kazakhstan border). The current range of EAB in Europe includes Luhansk Province of Ukraine and 18 provinces of Russia: Astrakhan, Belgorod, Bryansk, Kaluga, Kursk, Lipetsk, Moscow, Orel, Ryazan, Smolensk, St. Petersburg, Tambov, Tula, Tver, Vladimir, Volgograd, Voronezh, and Yaroslavl. Within these, only seven quarantine phytosanitary zones in five provinces are declared by the National Plant Protection Organization of Russia. EAB was not found in the regions along the Middle Volga: Mari El, Chuvash and Tatarstan republics, Nizhny Novgorod, Samara and Saratov provinces. The infested sites in St. Petersburg and in the Lower Volga basin are range enclaves separated from the core invasion range by 470 and 370 km, correspondingly. It is possible that new enclaves can appear in the cities of Eastern Europe and Kazakhstan far from the current known range. All previously known infestations in European Russia were in green ash (Fraxinus pennsylvanica), which was introduced from North America, and individual trees of European ash (F. excelsior). A first confirmed case of mass decline of several thousand of EAB-infested European ash trees in Moscow province is provided. Therefore, there is no more doubt that under certain conditions EAB can seriously damage native ash trees in European forests.


2007 ◽  
Vol 33 (5) ◽  
pp. 338-349
Author(s):  
Andrea Anulewicz ◽  
Deborah McCullough ◽  
David Cappaert

Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), a phloem-feeding insect native to Asia, was identified in 2002 as the cause of widespread ash (Fraxinus) mortality in southeast Michigan, U.S. and Windsor, Ontario, Canada. Little information about A. planipennis is available from its native range and it was not known whether this invasive pest would exhibit a preference for a particular North American ash species. We monitored A. planipennis density and canopy condition on green ash (F. pennsylvanica) and white ash (F. americana) street trees in four neighborhoods and on white and blue ash (F. quadrangulata) trees in two woodlots in southeast Michigan. Green ash street trees had significantly more canopy dieback and higher A. planipennis densities than white ash trees growing in the same neighborhood. Density increased by two- to fourfold in both species over a 3-year period. Canopy dieback increased linearly from 2002 to 2005 as A. planipennis density increased (R 2= 0.70). In each of the woodlots, A. planipennis densities were significantly higher on white ash trees than blue ash trees. Woodpecker predation occurred in all sites and accounted for 35% of the A. planipennis that developed on trees we surveyed. Results indicate that surveys for A. planipennis detection in areas with multiple ash species should focus on the relatively preferred species.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1509
Author(s):  
Nickolas N. Rajtar ◽  
Benjamin W. Held ◽  
Robert A. Blanchette

The emerald ash borer (EAB, Agrilus planipennis) is a devastating invasive pest that has killed millions of ash trees in the United States and Canada. EAB was discovered in the US in 2002 and first reported in Minnesota in 2009. It attacks ash trees that are native to the United States, including Fraxinus americana (white ash), F. nigra (black ash) and F. pennsylvanica (green ash). It also attacks Chionanthus virginicus (white fringe tree). Seven species of fungi isolated and identified only from EAB-infested trees in a previous study as having the potential to cause cankers were used to test their pathogenicity in F. americana (white ash). The fungi used were Cytospora pruinosa, Diplodia mutila, Diplodia seriata, Paraconiothyrium brasiliense, Phaeoacremonium minimum, Phaeoacremonium scolyti, and Thyronectria aurigera. Two field experiments that used F. americana used two inoculation methods: woodchip and agar plug inoculations. Results indicated that all of the fungi tested caused cankers in varying amounts, as compared to the controls. The largest cankers were caused by D. mutila (270 mm2), C. pruinosa (169 mm2), and D. seriata (69 mm2). All fungi except for T. aurigera were re-isolated and sequenced to confirm Kochs’ postulates. Canker-causing fungi found in association with EAB galleries have the potential to contribute to tree dieback and mortality.


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